Hidden ecosystem An ancient lake hidden deep beneath West Antarctica's ice sheet may reveal vital clues about climate change and future sea level rises, and uncover new forms of life, according to a UK team.

This month a group of scientists and engineers will travel to the ice sheet above Lake Ellsworth, which is buried under 3 kilometres of ice, in the first stage of a project costing more than 7 million pounds (AU$10.9 million).

The ice sheet covering the lake has trapped the Earth's geothermal heat, preventing it from freezing.

The team will prepare for a challenging drilling operation starting next November to collect water and sediment samples from the lake's floor, which will help scientists assess the stability of the West Antarctic Ice Sheet and future sea level rises.

"If we can find out if or when the ice sheet retreated or collapsed, it could tell us what kind of conditions would lead to a West Antarctic retreat in the future," says Professor Mike Bentley, a glacial geologist at Durham University.

For many years, scientists have speculated that new and unique forms of microbial life evolved in this dark, sterile and isolated environment which experiences temperatures of - 25°C.

Life as we know it?

The team expects to find evidence of viruses, bacteria, single-celled microorganisms called archea and complex cell organisms called eukaryotes.

These life forms could increase our understanding of how life on Earth began and evolved and help define its limits.

"Finding life in a lake that could have been isolated from the rest of the biosphere for up to half a million years will tell us so much about the potential origin of and constraints for life on Earth, and may provide clues to the evolution of life on other extra-terrestrial environments," says Dr David Pearce, science coordinator at the British Antarctic Survey .

"If we find nothing (it) will be even more significant because it will define limits at which life can no longer exist on the planet."

Contamination concerns

However, some experts worry that penetrating such untouched environments could alter them for good.

To avoid contamination, the Lake Ellsworth Programme's water probe and hot water drill will use clean technology derived from space science, the team says.

The project, mostly funded by the UK's Natural Environment Research Council, hopes to be the first to take samples and measurements from one of Antarctica's 387 known subglacial lakes.

Other research teams have been racing to penetrate such lakes after satellite data in the 1990s uncovered the hidden network in Antarctica.

Russian scientists are currently forced to wait until December to resume drilling at East Antarctica's Lake Vostock, after the end of summer this February cut short their operation.

A US project is concentrating on the Whilland Ice Stream in West Antarctica, but it is unlikely to gain entry to the lake until next year.